As always, generalising from anecdotes can be dangerous. I am married to a christian, and have occasion to meet both non-religious and religious people. I see a wide variety of mental behaviours in them, with depressive and positive in both communities. In most cases these behaviours actually have their root in (I suspect) other parts of their background.

What I will agree with is that religousity can encourage people to be more altruistic than they might be otherwise. While a rationalist might carefully reach the same results, it is a more difficult course to enter without getting caught up in simple selfish action. That said, the bonus of group altruism brings with it distate for outsiders, and a slavish devotion to a set of behaviours that the group has decided are "good"